This invention belongs to the field of electronic cycle computers. Typically, these computers comprise a compact, lightweight housing with a display screen and a clamp for mounting it on a bicycle handlebar, one or more orbitally movable magnets carried by the spokes on the front or rear wheel, and a signal detector mounted on one of the front fork tubular legs or a rear stay tube at a position adjacent the orbital path of the magnet or magnets. The computer has an inbuilt clock and, based on a known size wheel, processes signals from the detector to display useful information such as current and maximum speeds, distance traveled, and current and elapsed time.